Amalgamating flat and associated parking space land registry titles

Hi

My partner and I are currently trying to re-mortgage our property (a leasehold flat) which we also have a parking space. The two are on separate deeds ie Land Registry Title 1) Leasehold Flat 2) Parking space associated with the Leasehold Flat

When we bought the flat and parking, our original lender gave us a mortgage over both

However, now they are saying they can only re-mortgage us over one title deed ie the leasehold flat, which is dropping our overall property value (as it now isn't including the parking space) and pushing us to a higher LTV, which is causing us issues

We are concerned other lenders will say something similar, so i was wondering if its possible to amalgamate the two title deeds into one ie 1 title deed for the leasehold flat and the associated parking space? Is this possible and a good enough reason for an amalgamation to be accepted?

We don't have any 'evidence' other than telephone conversations so far, although i could speak to my current lender to get it in writing, however we don't want to have a failed re-mortgage application just for the sake of having some evidence due to the detrimental impact it would have on our credit rating to have a failed re-mortgage

And to clarify, the parking space is in an underground communal parking area, however we have the legal deed for a specific parking space within the car park (and the title deed says associated parking space of our flat name and number)

Jake - you can request amalgamation and explain the reason for doing so. The reason cited should be sufficient but we won;t know for sure until both titles/tenures are looked at and considered.
If there's an urgency as need to remortgage and the offer is going to run out you should then request expedition as a second stage